Insulation cutter



NOV- 2, 1943- J. F. cos'rELow V 2,452,734

INSULATION CUTTER- Filed OOt.' 26, 1945 E #l -l E: E 4 3.26 i 46* 0 e 2 24 l I E .4-

iatented Nov. 2, 1948 tgig illtil'il) STATES .FTENTOFFICE INSULATION GUTTER John F. Costeldw, Kansas City, Mo.

Application October 26, 1945, Serial No. 624,820

4 Claims.

My invention relates to a new and useful device whereby the insulating coverings of single and multiple wire cables can be quickly stripped from the ends or any other portion of said cables for all purposes such, for instance, as splicing the cables or connecting them to various electrical instruments.

My device is capable of accommodating insulations of different thicknesses and diameters and is adapted to act upon various kinds of insulation, such, for example, as fabrics, lead sheathings and all rubber insulations.

In the use of my device a -blade is employed for slitting the insulation of a Vcable longitudinally any desired length and then cutting the insulation circumferentially at one or both ends of the slit, so that the slitted portion can be easily peeled ofi the cable with the fingers. The blade also enables slitting of the main outer insulation without danger of cutting or otherwise damaging the inner insulation of single or multiple cables. The blade is inclosed in a frame having a tubular guide for the insulated cables which also protects the fingers from coming into contact with the blade and being cut thereby. Interchangeable inserts of various diameters and adapted to t in the tubular guide, or each other, are provided for cables of Vdiiferent diameters to keep the latter from turning axially or shifting laterally and thereby becoming damaged While -being slit.

In order that the invention may be fully u nderstood, reference will now be had to the accompanying drawing, in which- Fig. 1 is a side elevation of the device.

Fig. 2 is a broken top plan View thereof.

Fig. 3 is a broken longitudinal section on line 3 3 of Fig. 2.

Fig. 4 is a cross section on line 4-4 of Fig. 2.

Fig. 5 is a detail perspective View of the blade and a holder therefor.

Fig. 6 is a fragmentary top plan view of a tubular guide.

Fig. 7 shows a fragment of a small cable with the insulation slit longitudinally and cut circum-l ferentially.

In order to avoid confusion in the following description and claims as to the position and direction of movement of parts, it will be assumed that the device is disposed in a horizontal position as disclosed by Fig. l.

In carrying out the invention I employ a frame 2 having a vertical recess 4 in its upper portion and a bore 6 extending longitudinally thro-ugh its lower portion. The bore 6 is provided with a tubular guide 8 of suitable length firmly secured 2 at oneend within said bore `and adapted to guide cables when their insulation is being slit. Figs. 1,-2 and 4 disclose a large cable A in the tubular guidell, comprising a multiple of insulated wires A enclosed in insulation A2.

For cables A3, Figs. 3 and 7, too small in diameter to be properly guided in the tubular guide 8, a tubular insert lil is provided that removably ts within the guide 8, Fig. 3, and if desired smaller inserts may be provided that removably nt within each other.

Adjustably mounted Within the recess 4 is a blade holder I 2 provided at its lower portion with a notch It. extending from front to rear of the blade holder, Figs. 3 and 5, and inwardly from one side to about the center of the holder to receive a blade I6 having an inclined cutting edge I8. The blade I5 is removably secured in the notch I4 Iby suitable means, such as screws 2B, so

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that on becoming dulled by use the blade can be removed and sharpened for further use, or discarded for another sharp blade.

'Ilhe blade holder I2 is adapted to be adjusted up or down by means of a hand lever 22 and links 22, for use on cables of diiferent diameters and insulation of different thicknesses. The hand lever 22 is disposed longitudinally above the tubular guide 8 and provided with a bifurcated end 26 operably connected to opposite sides of the frame `2 by pivotal means 28. Each link 24 is operably connected at its lower end to the adjacent side of the bifurcated portion 26 by pivotal means 29, and operably connected at its upper end to one side of the blade holder I2 by appropriate means such as a thumb screw SII, which extends freely through an aperture 32 in the link and a s lot 34 in the adjacent side of the frame 2, 'Ighe inner ends of the thumb screws 30 are tapered toppoints and threaded into opposite ends of a small bore 36 extending transversely through the blade holder I2.

The blade I@ extends downward into the path of the insulation A2, Fig. 4, which is to be slit longitudinally as shown at B on the small cable A3, Fig. 3, through registering slots 38 and 40 in the frame 2 and the tubular guide 8, respectively. 'Ihe slots 3S and 4,0 `parallel the axis of the tubular guide 8 and their middle portions intersect the middle portions of transverse slots 22 and 44, like the intersecting slots 52 and 54 of the insert It, Fig. 6. The slots in the frame 2 register with the corresponding slots in the guide 8 and, like the slots 38 and fili, extend through the frame 2 and the tubular guide 8, respectively. The foregoing arrangement of the slots 42 and A4- permit the blade to be set transversely to the insulation A2 and cut the latter circumferentially ,at one end of slit B, as shown at C on the small `gcable, Fig. '7, so that the slit portion can be readily removed from the ca-ble.

In order that the blade I6 may be adjusted to accommodate outer insulations A2 of different ,thicknesses and diameters and avoid damaging the inner insulation of 4the Wires A', Fig. 4, T neans are provided for checking the downward `movement of the blade comprising a stem 46, projecting from the upper end oi the blade holder I2, and a rotatable element 4B threa-ded upon said stem and adapted to contact the upper surface of the frame 2 when the blade has penetrated the insulation. The rotatable element 48 may be adjusted to any predetermined point upon the stem 46, which has a vertical slot 50 so that the opposite sides of the stem may spring apart suiliciently to frictionally hold the rotatable element at any point to which it may be adjusted.

The operation briefly stated is as follows: When the insulation A2 of the cable A is to be slit longitudinally as above stated, the lever 22 is pulled upward to lift the blade holder I2 and the blade i6 until the lower end of the latter is withdrawn from the slot 49 in the 'tubular guide 8, or the slot 52 when the tubular guide 8 is provided with a tubular insert lll, as shown by Fig. 3, The cable is then inserted in the front end of the tubular guide 8, or insert l0, the proper distance, as shown by Fig. 3,V after which the lever 22' is pushed downward to 4lower the blade holder IZand force the lower end of the blade I6 through the insulation A2, when further downward movement is checked by the rotatable member 48 contacting the upper surface of the frame 2. The cable A is then grasped and withdrawn through the left end of the guide 8, during ywhich operation the insulation A2 is slit longitudinally to the right hand end of the cable. The thumb screws Sii are now removed from the blade ,holder l2, and the latter, together with the blade I6, is lifted from the frame 2 and turned one-fourth of va revolution, thenV replaced in theframel 2 where the blade holder is secured by screwing the inner 'ends of the thumb screws 3B into a bore 53 extending through the blade holder and intersecting the bore 3E. When replacing the blade holder i2, as stated, the blade is reinserted in the guide it through slots 42 andl 44 and the cable A is adjusted longitudinally until the left end of the slit B is beneath the blade I6, which lis then forced through the insulation A2, as above stated. If the cable is too long to conveniently rotate aXially, my device is rotated around the cable until the insulation A2 has been cut circumferentially, so that when the cable is withdrawn from the guide the slit and cut portions B and C, respectively, .may be readily removed with the lingers.

From the foregoing description it lis apparent that I have provided a device which is well adapted for the purpose intended and while `I have shown a preferred form of the invention I reserve'all rights to such changes and modificathe invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An insulation cutter comprising a frame having guide means through which a cable incased in insulation can be drawn, a blade adapted to be moved into the path of the insulation to slit the latter longitudinally as the cable is drawn through said guide means, a blade holder operably mounted in the frame and carrying the blade, a manual lever operably connected to the frame, links pivotally connected at one end to the lever, and pivotal means extending through slots in opposite sides of the frame and connecting the links to the blade holder.

, 2. An insulation cutter comprising a frame provided with a recess and a bore which latter eX- tends longitudinally through the frame, guide meansv secured in said bore and provided with anaperture registering with an aperture extending fromthe bore to the recess, a blade holder in said recess, and a blade carried by said blade holder adapted to project through said apertures into the path of insulation on a cable being drawn from ysaid guide means.

3. `An insulationy cutter comprising a frame, guide means secured in the frame and through which a cable incasedin insulation can be drawn, a blade extending into the path of the insulation through an aperture in the guide means and adapted to cut the insulation as the cable is drawn through said guide means, a blade holder operably mounted in the frame and carrying the blade, means associated with the frame and the blade holder and adapted to move the latter toward or awayfrom the guide means, and means associated with the rame and the blade holder for checking the blade holder when `the blade has entered the guide means to a predetermined point.

4. AnV insulation cutter comprising a frame, guide means 'secured in the frame and through which a cable incasedin insulation can be drawn, a blade extending into the path of the .insulation through an aperture in the guide means and adapted' to cut the insulation as the cableV is drawn .throughl said guide means, a blade holder operably mounted in the frame and carrying the blade, means associated withthe frame and the JOHN F. CosTELOw.

REFERENCES CITED The following references yare of record in the file of this patent:

' UNITED STATES PATENTS Number I Name Date 2,235,575- Edwards :M2312l 18, 1941 2,353,173 Martn July l1y 1944 

